ELSGOLTS L <br/><br/>
Differential equations and the calculus of variations 
ELSGOLTS L 
 - Moscow  Mir Publishers           1970 
 - 440p.  cm. 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>B33.N70, L0/SC